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/*
* This file is part of choco-solver, http://choco-solver.org/
*
* Copyright (c) 2020, IMT Atlantique. All rights reserved.
*
* Licensed under the BSD 4-clause license.
*
* See LICENSE file in the project root for full license information.
*/
package org.chocosolver.solver.search.loop.move;
import org.chocosolver.memory.IEnvironment;
import org.chocosolver.solver.Solver;
import org.chocosolver.solver.search.strategy.decision.Decision;
import org.chocosolver.solver.search.strategy.strategy.AbstractStrategy;
/**
* A move dedicated to run an Depth-bounded Discrepancy Search[1] (DDS) with binary decisions.
*
* [1]:T. Walsh, Depth-bounded Discrepancy Search, IJCAI-97.
*
*
* Note that the depth is not maintained since it is useful only when max discrepancy is greater than max depth,
* which should not happen.
* Created by cprudhom on 07/10/15.
* Project: choco.
* @author Charles Prud'homme
* @since 3.3.1
*/
public class MoveBinaryDDS extends MoveBinaryLDS {
/**
* Create a DFS with binary decisions
*
* @param strategy how (binary) decisions are selected
* @param discrepancy maximum discrepancy
* @param environment backtracking environment
*/
public MoveBinaryDDS(AbstractStrategy strategy, int discrepancy, IEnvironment environment) {
super(strategy, discrepancy, environment);
}
@Override
public boolean extend(Solver solver) {
boolean extended = false;
Decision current = strategy.getDecision();
if (current != null) { // null means there is no more decision
solver.getDecisionPath().pushDecision(current);
solver.getEnvironment().worldPush();
if (dis.get() == 1) {
solver.getDecisionPath().getLastDecision().buildNext();
}
dis.add(-1);
extended = true;
}
return extended;
}
}